Multiple choice general knowledge math & puzzles

The difference of 2 positive numbers is 80 and quotient obtained on dividing the one by the other is 9. Find the first number.

  1. 75

  2. 90

  3. 10

  4. 80

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let the numbers be x and y, where x > y. Then x - y = 80 and x/y = 9, so x = 9y. Substituting: 9y - y = 80, so 8y = 80, giving y = 10. Then x = 9*10 = 90. The first number (x) is 90. Verification: 90 - 10 = 80 ✓ and 90/10 = 9 ✓.